Results indicated both direct and indirect significant effects of parental knowledge on adolescent’s aggressive and delinquent behavior. Specifically, the findings reveal that the less parents know about the whereabouts and activities of their children, the more problem behavior the adolescent exhibits. Additionally, links between parent and peer context were observed that indicated a combined effect of parental knowledge and peer contacts on problem behavior. These findings suggest that adolescents who have negative relationships with their parents tend to associate with deviant peers, which in turn predicts increases in problem behavior. Gender differences were noted in that decreasing levels of parental knowledge were related to increasing levels of peer contact for boys but not for girls. Future research should be conducted in different populations of youths. Participants were 457 13- to 14-year-old adolescents attending 3 secondary schools in the Netherlands. Participants completed questionnaires regarding their parents, peers, and problem behaviors at 3 different data collection times with 1-year intervals. Data were analyzed using LISREL 8.54 and a Latent Growth Curve modeling approach. Tables, figures, footnotes, references